Vortex separator

ABSTRACT

A vortex separator is provided having an annular contaminant chamber for receiving centrifugally separated particles, and a baffle at the entry to or in the annular chamber, to inhibit the whirling of particles retained therein, to prevent abrasion of the walls by the spinning particles, while not interfering with the entry of the particles into the annular chamber.

This application is a continuation-in-part of Ser. No. 360,516, filedMay 15, 1973, now U.S. Pat. No. 3,895,930 granted July 22, 1975, whichin turn is a continuation-in-part of Ser. No. 306,119, filed Nov. 13,1972, which is a continuation of Ser. No. 31,471, filed Apr. 24, 1970,both now abandoned.

Vortex separators comprise a tube through which particle-laden air ispassed, and a vaned deflector disposed within the tube in the path ofthe influent air stream to impart a helically spinning or cyclonicmovement to the air stream. The air-entrained dirt particles that arerelatively heavy are thrown to the periphery of the tube, due to thecentrifugal force of the vortex stream, thus cleaning the air ofparticles at the center of the tube. The clean air at the center isnormally drawn off from the center of the tube, and theperipherally-disposed dirt particles drawn off from or collected at theperiphery of the tube.

In such vortex separators, the clean air outlet is in the form of a tubeof lesser diameter corresponding to the central clean air zone, andcoaxial with and extending into the larger diameter vortex tube. Theperipheral vortex flow with the entrained particles enters an annularpassage open at each end and surrounding the clean air outlet tube, andthe particles are normally drawn off from the end of this by bleed orscavenge flow. It is, however, necessary to maintain flow through theannular passage, to prevent it being clogged by contaminants depositedthere, and ensure that the contaminants are carried off by the flow.

Brandt Austrain Pat. No. 192,385 describes one way to overcome thisproblem. Brandt uses a vortex separator of conventional type, having atubular outlet member tapping the clean air flow in the center of thevortex, in which the helical flow of the gases in the vortex is utilizedto maintain the contaminants entrained in the gas in the annular passagesurrounding the outlet member. The end walls of the annular passage areprovided with a helix or spiral whose pitch conforms to the vortex ofthe contaminant-bearing gases, so as to maintain spiralling flow throughthe passage. To achieve this, the helix or spiral is placed midwaybetween the ends of the annular passage. The openings at each end of thepassage are unobstructed, so that the spiralling flow keeps the openingsfree of contaminant deposits at all times, as well as keeping theannular passage free of such deposits.

The efficiency of a vortex separator (i.e., the percentage of entrainedparticles that are separated) is a function of the centrifugal forcesdeveloped, the length of the spinning zone, and the proportion of thescavenge flow to clean air flow. Of course, an optimum clean air flow isalways the primary desideratum. Therefore, the flow of scavenge airshould be controlled at the minimum to give effective particleseparation.

The measures required to control and limit scavenge flow create problemswhich heretofore have not been resolved when operation atsuperatmospheric pressure is desired. When a vortex separator isoperated at a high superatmospheric pressure, as for example whencleaning bleed air taken from the compressor of a gas turbine or jetengine, one way of limiting scavenge flow is to close off all or most ofthe outlet end of the annular passage to form an annular contaminantchamber and to exhaust the scavenge flow therefrom through a relativelysmall diameter opening, disposed in the side wall or at the closedbottom or end of the chamber. The flow rate of the scavenge air throughthis opening and the back pressure should be sufficient to give theneeded efficiency of the separator. Control over the scavenge air flowrate and pressure is maintained by selection of the diameter of thescavenge air opening, or by providing an orifice at the scavenge airopening or by providing an adjustable value in the scavenge air opening.Where the supply of air is limited it may be desirable not to bleed aportion as scavenge flow. In such cases a scavenge air opening mayeither not be provided or be kept closed and the separated particlesretained within the annular contaminant chamber.

If a scavenge opening is not provided, is closed or becomes plugged, asby a particle too large to pass through, the particles that are throwncentrifugally into the peripheral cyclonic flow continue to enter theannular chamber, are retained there, and are subjected to a continuedcyclonic or spinning flow. However, since they cannot escape from thechamber, they continue to whirl therein, and abrade the walls of thevortex tube within the annulus. This creates a serious problem. Evenwhile scavenge flow continues particles too large to pass through thescavenge air opening may whirl around the annular passage continuously,also resulting in abrasion. Eventually, the abrasion caused by thespinning particles will wear away the wall of the vortex tube, and causethe tube to fail.

Such a failure, depending upon the system in which the vortex separatoris utilized, can be catastrophic, and therefore must be prevented. Forexample, high pressure bleed air from the compressor is often employedin gas turbine or jet engines, to maintain the oil in the bearinghousing in contact with the bearings. The need for providing clean airis of course obvious, inasmuch as contaminant particles in contact withthe bearings can cause excessive wear and are quite dangerous. A vortexseparator inserted in the high pressure air line would be a usefuldevice to provide clean air. However, a failure in the vortex separatorin the line leading to the bearings can cause loss of pressurization,resulting in separation of the oil from the bearings, thus causing thebearings to overheat, and possibly cause a fire. If the engine is in useon an aircraft at the time of such a failure, it can cause loss of theaircraft. Therefore, a vortex separator cannot be put to such a useunless this abrasion problem is overcome.

Another difficulty presented when there is lack of scavenge flow is thatthe particles which build up within the annular chamber may be swept outthe open entrance, sometimes suddenly, and en masse, by the enteringcyclonic flow, and then enter the clean air stream. This, of course, canbe quite detrimental to downstream components in the system, and if theparticles do so en masse the effect can be worse than if the vortexseparator merely became inoperative.

In accordance with the present invention such difficulties are overcomeby providing a vortex separator having an annular contaminant chamberand a baffle at the entry to the chamber or in the chamber, effective toinhibit the whirling of particles retained in the annular chamber, whilenot interfering with the entry of such particles into the chamber, undernormal conditions. As another feature, the baffle may also be designedas a closure to prevent the retained particles which build up within thechamber from being swept out into the clean air stream by the cyclonicflow in the vortex tube.

The vortex separator of the invention comprises a tubular body having aninlet at one end, and outlet at the opposite end, and a central passagetherebetween; a deflector coaxially mounted in the passage adjacent theinlet, and having a plurality of helical vanes abutting the wall of thepassage, and positioned at an angle to the line of flow from the inletto the outlet so as to create a vortex stream in the influent air, whichconcentrates the contaminant particles in the whirling air stream at theperiphery of the passage, thereby leaving the air at the center of thepassage relatively clean; a generally tubular outlet member disposedwithin the central passage at the outlet end of the tubular body fordelivery of clean air from the central passage of the tubular body; saidtubular outlet member defining an annular contaminant chamber betweenthe exterior of the outlet member and the interior wall of the centralpassage of the tubular body for receiving separated contaminantparticles; a wall extending between the tubular outlet member and thetubular body at the end of the annular chamber at the outlet end of thetubular body, closing off the annular chamber at that end; and a bafflehaving at least one opening and defining an inlet into the annularchamber and disposed in the line of cyclonic flow at or in the annularchamber and effective to deflect the whirling air stream in a manner toinhibit the whirling movement of the particles retained in the chamber,and thus prevent abrasion of the wall of the tubular body there,substantially without interfering with the entry of particles into thechamber. There is no outlet port from the annular chamber.

Preferred embodiments of the vortex separator of this invention areillustrated in the drawings, in which:

FIG. 1 is a cross-sectional view of a vortex separator having a bafflein the form of a helical ring;

FIG. 2 is an isometric view of the helical ring baffle utilized in thevortex separator of FIG. 1;

FIG. 3 is a cross-sectional view of another embodiment of baffle in theform of radial fins;

FIG. 4 is a cross-sectional view taken along the line 4--4 of FIG. 3,and looking in the direction of the arrows, showing the fins;

FIG. 5 is a cross-sectional view of another vortex separator havingfins;

FIG. 6 is a cross-sectional view taken along the line 6--6 of FIG. 5,and looking in the direction of the arrows, showing the fins;

FIG. 7 is a cross-sectional view of another embodiment of vortexseparator utilizing the helical baffle of FIG. 2.

The baffle can be of any construction that obstructs whirling movementin the annular chamber, and provides an entrance into the chamber forcontaminant particles.

It is particularly important that the baffle not unduly obstruct orinterfere with entry of entrained particles into the chamber, and ensurethat the particles retained in the chamber be quiescent, so that theywill not cause abrasion damage.

The baffle can take a form such that it separates the spinning velocityand longitudinal velocity components of air and/or particles enteringthe annular chamber so that spinning particles can pass in freely. Thebaffle can also permit spinning flow to enter the annular passage, andalso block or inhibit whirling of the retained particles, or it canredirect spinning flow so that it becomes direct flow.

An example of the first-mentioned form of baffle is a flat ring closingoff the annular chamber at the entrance thereto or a short distancetherewithin. The ring has one or more apertures through which all flowthat enters the annular chamber must pass.

The size of the apertures in the ring should be large enough to permitall separated particles, whatever their size, to enter. A flat ring ofthis type is effective by permitting the entry of particles through theaperture only in a direct path. The whirling air at the periphery of thevortex tube has little tendency to pass through the baffle into thechamber, since there is no outlet from the chamber. Therefore, oncewithin the chamber the centrifugal forces of the cyclonic flow no longeract upon the particles, so that they may harmlessly settle out withinthe chamber. As a practical matter, the air in the annular chamberbeyond the ring is relatively quiescent, and particles in the annularchamber are quiet, and will not abrade the walls of the tubular body.

The ring should completely close the entrance to the annular chamberexcept for the aperture or apertures which permit entry of scavenge flowand entrained particles. In this manner, the ring serves as a closure toretain the separated particles within the chamber. As the particlesbuild up within the chamber, the ring prevents their being swept out bythe cyclonic flow in the vortex tube.

In the simplest form, the ring is a flat washer, having a singleaperture through its solid portion. The outside diameter of the ring isapproximately equal to the inside diameter of the tubular body, and theinside diameter of the ring is approximately equal to the outsidediameter of the tubular outlet member, so that when installed it closesoff the greater part of the inlet to the annular chamber. The flat ringshould be disposed a short distance within the annular passage anddefines the inlet end of the annular chamber. This ensures that whirlingparticles which strike the ring will be held on the ring, will travelcircumferentially thereon until they can reach and enter an aperturethereof, and will not be deflected into and entrained in the clean airflow prior to their passage through the aperture into the annularchamber.

The ring can also be disposed at an angle to the axis of the vortexseparator. If the angle is approximately equivalent to or greater thanthe helix angle of the vaned deflector, one segment of the ring isparallel to the plane in which the whirling particles move, and if theaperture is located on this segment, at right angles to the plane offlow, the entrained particles will have to change direction by a 90°angle to pass through the aperture. Moreover, such an aperture preventsentry of the cyclonic flow, and inhibits whirling within the annularchamber.

If the angle is less than the helix angle of the deflector and theaperture is on a segment of the ring which is opposed to the directionof whirling the whirling particles pass through the aperture readily,due to their centrifugal momentum, but the cyclonic flow does not, andthe cyclonic flow forces acting upon the particles within the chamberare thus greatly diminished by the presence of the ring, since thewhirling air has little tendency to pass through the aperture to enterthe chamber. The ring is thereby effective to inhibit the whirling ofthe particles trapped within the chamber.

It may be necessary to provide more than one aperture in the ring. Whena plurality of apertures are employed, each must conform to the propersize requirements to permit the passage of the entrained particles.

The apertures can have any convenient shape, such as round, square orrectangular. They can be formed by drilling, punching, slitting orperforating, or cutting out a segment of the ring. Preferably, arcuateshaped openings extending radially across the annular passage from theinside wall of the tubular body to the outside wall of the tubularoutlet member are utilized to allow the particles easy access to theopening. An arcuate aperture can be formed simply by splitting the ringin one portion and adjusting the size of the gap by removing a radialsegment.

The baffle can also take the form of a split ring, formed into asingle-coil helix, resembling a lock washer, wherein the size of theaperture varies according to the pitch of the helix, and the gap betweenthe split ends of the ring. Such a helix can have a pitch eitherparallel or opposed to the direction of whirling. If the aperturebetween the ends of the helix is such that the whirling air stream mustchange direction, in order to pass through the aperture, the particleswill not enter readily, thus inhibiting their whirling motion. If theaperture in the helical ring faces the oncoming flow in the whirling airstream, the particles enter readily, and the baffle is effective toinhibit their whirling within the chamber. A helical baffle of thislatter type is preferred since, while permitting the easy entry of theparticles, the helix effectively prevents the particles which build upin the chamber from being swept out.

If a helical baffle in which the aperture faces the whirling air streamis used in a vortex separator employing scavenge flow to exhaust theseparated particles, the pitch of the helix may be less than the pitchof the helical vaned deflector. In this manner the angular directionchange required for the flow and entrained particles to pass through canbe sufficient to inhibit whirling of large or heavy particles which aretrapped and retained within the chamber.

The ring, whether flat or helical, can be secured within the annularpassage by welding, brazing, bonding or by press fit. It may also beformed as an integral flange on the entrance end of the clean air outlettube. Other suitable means for attaching or forming the ring will beapparent to those skilled in the art.

The baffle can also be in the form of radial fins which extend partiallyor completely across the annular chamber parallel to the axial flowtherethrough, and either partially or completely from end to end of theannular chamber. When the whirling stream enters the annular chamber,whirling is halted by the obstructing fins, and direct axial flowresults. Since the fins extend radially across the annular chamber theydo not obstruct axial flow of entrained particles, nor are the entrainedparticles deflected into the clean air outlet.

When the fins extend partially across the annular chamber, they can befixedly attached to either the outside wall of the clean air outlet tubeor the inside wall of the separator body, or preferably both whereinthey are alternately attached to the body and the outlet tube, so that awhirling stream will have a tortuous path to follow, but a direct flowhas free passage. The fins should extend radially sufficiently acrossthe annular chamber to ensure that a complete circular path is notavailable to the whirling flow. Similarly, the fins should extendlongitudinally within the annular chamber a distance sufficiently toensure that the whirling air must make contact therewith during onerevolution of the whirling air. The entrained particles also aredeflected by the fins. The particles remain quiescent at the bottomportion of the annular chamber.

When the fins extend completely across the annular chamber, they can befixedly attached to both the separator body and the clean air outlettube, so as to form a plurality of segmented annular chambers. Thewhirling flow that enters the annular chambers can only flow axiallytherethrough, since the fins prevent the circular movement of the flow.

The number of fins required to inhibit or stop the whirling of thewhirling air stream is dependent upon factors such as the angle of thefins, the diameter of the annular chamber, the flow rate, the pressure,and the spacing of the fins in the annular chamber. Three fins extendingradially completely across the annular chamber and disposedapproximately 120 degrees apart are satisfactory to inhibit whirlingwithout adversely effecting the particle separation efficiency. Suchfins can extend longitudinally to the outlet end of the chamber.

Preferably, the baffle, whether it be in the form of an apertured ringor radial fins, is formed from the same or similar material as thevortex separator, to facilitate its welding, brazing, bonding orpress-fitting in place. By utilizing the same material as the separator,both will be subject to the same contraction and expansion, due totemperature changes. Since high pressure vortex separators are oftenused in high temperature systems, this is an important consideration.Usually, vortex separators for high pressure and temperature systems canbe constructed from metallic material, such as steel, stainless steel,aluminum, nickel alloys and the like. Where temperature and pressurerequirements are not extremely high, abrasion-resistant plasticmaterials, such as nylon, polytetrafluoroethylene, polypropylene,polycarbonate and polyphenylene oxide resins can be utilized.

The design of the tubular body, the vaned deflector and the clean airtubular outlet member are important for the efficient operation of thevortex separator. It should be noted that the design of the baffle ofthe invention can be adapted to fit the design requirements of any ofthe other components. Therefore, the baffles can be efficiently utilizedin high pressure vortex separators of varying design, and willefficiently inhibit whirling in the annular contaminant chamber thereofso as to prevent the abrading of the body tube walls by whirlingparticles.

The vortex separator shown in FIG. 1 comprises a tubular body 1 with anopen central portion or vortex chamber 5, and formed of stainless steel,and having an inlet 2 for high pressure contaminated air, and an outlet3 for clean air, but no scavenge flow outlet. A vaned helical deflector6 is disposed within the center of the tubular body 1 to generate avortex stream in the influent air which concentrates the contaminantparticles in the whirling air stream at the periphery of the passage 5,thereby leaving the air at the center of the passage relatively clean.The outlet 3 has a tubular outlet member 7 which has a peripheral flange9 extending to the wall of the tubular body 1 and terminating in aperipheral recess 9a, receiving the end of the tubular body. The outletmember 7 extends into the open central portion 5 of the tubular body 1.The tubular member 7, flange 9 and the inside walls of the tubular body1 define an annular chamber 8 for the reception of the contaminantparticles. The flange 9 walls off the outlet end of the annular chamber8 so that there is no exit therefrom.

A baffle in the form of a helical ring 10 having aperture 11 is disposedwithin the entrance to the annular chamber 8. The ring extends from theoutside wall of the tubular member 7 to the inside wall of the tubularbody 1, so that all air that enters the annular chamber 8 must passthrough the aperture 11. As shown in FIG. 2, the ring 10 is a singlecoil helix resembling a lock washer. The helical ring 10 is installedjust within the entrance to the annular chamber 8, and has a pitchdirection the same as the vortex stream, so that the aperture 11 facesthe whirling stream, and the contaminant particles can freely passtherethrough.

In operation, the vaned deflector 6 generates a vortex stream in thecontaminated influent air that enters via inlet 2. The vortex streamconcentrates the contaminant particles in the whirling air stream at thewalls of the tubular member 1, thus allowing them to enter annularchamber 8 via aperture 11 in the helical ring 10, and be collectedthere, since there is no scavenge flow outlet. The clean air in thecenter of the vortex is tapped by outlet member 7 and is thus dischargedvia port 3. The helical baffle 10 is effective to inhibit the whirlingmovement of the particles retained within the chamber 8. The particlescontinue to freely pass through the aperture 11, due to theircentrifugal momentum, but once inside the chamber 8 the baffle 10 ofchamber 5 prevents the particles from being subjected to the cyclonicflow forces above the outlet member 7. The whirling motion of the air atthe periphery of the vortex tube does not continue past the baffle 10,due to the absence of a scavenge flow outlet from the chamber 8. Forthis reason, the particles that enter the annular passage 8 will bequiescent, and failures caused by abrasion of particles against the wallof the tubular body 1 are averted.

In addition, the helical baffle 10 prevents the particles that areretained in the annular chamber 8 from escaping in the reversedirection, to return to the vortex chamber 5. The baffle 10 prevents thewhirling air stream in the vortex chamber 5 from sweeping the collectedparticles out of the annular chamber 8. This permits the particles to bestored in the chamber until it is full, at which time it can be manuallycleaned out.

It is thus evident that the vortex separator of FIG. 1 is effectivewithout a scavenge flow bleed of separated particles. The separatedparticles are stored within the chamber 8, and the helical baffle 10inhibits their whirling to prevent abrasion of the chamber wall.

The baffle provided in the vortex separator shown in FIG. 3 are radialfine 15 and 16 which extend partially across the annular chamber 8, andare effective to inhibit whirling of separated particles. Fins 15 arefixedly attached to the outlet tube 7 and are disposed approximately120° apart. Fins 16 are fixedly attached to the separator body 1approximately 120° apart, and are disposed alternately between the fins15. Fins 15 and 16 both extend sufficiently across the annular chamber 8in an overlapping manner so that a complete circular path is notavailable to the air flow within the annular chamber. As shown in FIG. 4the fins 15 and 16 extend longitudinally within the annular chamber 8 toa point which is just short of the closed end of the chamber. Inoperation, as the whirling stream enters the annular chamber it isdeflected by the fins, and proceeds in an axial flow path.

In the vortex separator of FIGS. 5 and 6 three radial fins 17 extendcompletely across the annular chamber 8, and all the way to outlet endwall 9' so as to form three segmented annular chambers 8a, closed at theoutlet end. Since the fins prevent circular movement of the flow, thewhirling flow can only pass axially through the chambers 8a. Thus, thewhirling stream is effectively dissipated, and damage to the separatorbody by whirling particles is prevented.

The vortex separator shown in FIG. 7 comprises a tubular body 21 with anopen central portion or vortex chamber 25, and formed of stainlesssteel, and having an inlet 22 for high pressure contaminated air, anoutlet 23 for clean air and no scavenge flow outlet. A vaned helicaldeflector 26 is disposed within the center of the tubular body 21 togenerate a vortex stream in the influent air which concentrates thecontaminant particles in the whirling air stream at the periphery of thepassage 25 thereby leaving the air at the center of the passagerelatively clean. The body 21 has an expanded portion 35 of largerdiameter at the outlet member 27 giving a large annular chamber 28, forgreater particle storage.

The outlet 23 has a tubular outlet member 27 which has a peripheralflange 29 extending to the wall of the tubular body 1 and terminating ina peripheral recess 29a in the end of the tubular body. The outletmember 27 extends into the open central portion 25 of the tubular body21. The tubular member 27, flange 29, and the inside walls of thetubular body 21 define an annular chamber 28 for the collection ofcontaminant particles. The flange 29 walls off the outlet end of theannular chamber 28, so that there is no exit.

A baffle in the form of a helical ring 30 having an aperture 31 isdisposed within the entrance to the annular chamber 28. The ring extendsfrom the outside wall of the tubular member 27 to the inside wall of thetubular body 21, so that all air that enters the annular chamber 28 mustpass through the aperture 31. As shown in FIG. 2, the ring 30 is asingle coil helix resembling a lock washer. The helical ring 30 isinstalled just within the entrance to the annular chamber 28, and has apitch direction the same as the vortex stream, so that the aperture 31faces the whirling stream, and the entrained particles can freely passtherethrough into chamber 28.

In operation, the vaned deflector 26 generates a vortex stream in thecontaminated influent air that enters via inlet 22. The vortex streamconcentrates the contaminant particles in the whirling air stream at thewalls of the tubular member 21, thus allowing them to enter annularchamber 28 via aperture 31 in the helical ring 30, and be stored there.The clean air in the center of the vortex is tapped by outlet member 27and is thus discharged via port 23. The helical baffle 30 is effectiveto inhibit the whirling movement of the particles retained within thechamber 28. The particles continue to freely pass through the aperture31, due to their centrifugal momentum, but once inside the chamber 28,the baffle 30 of chamber 25 prevents the particles from being subjectedto the cyclonic flow forces above the outlet member 27. The whirlingmotion of the air at the periphery of the vortex tube does not continuepast the baffle 30. For this reason, the particles that enter theannular passage 28 will be quiescent, and failures caused by abrasion ofparticles against the wall of the tubular body 21 are averted.

In addition, the helical baffle 30 prevents the particles that areretained in the chamber 28 from escaping in the reverse direction, toreturn to the vortex chamber 25. The baffle 30 prevents the whirling airstream in the vortex chamber 25 from sweeping the collected particlesout of the annular chamber 28. This permits the particles to be storedin the chamber until it is full, at which time it can be manuallycleaned out. The widened portion 35 of the tubular body 21 enlarges thechamber 28 providing a greater storage space for such particles.

Having regard to the foregoing disclosure, the following is claimed asinventive and patentable embodiments thereof.
 1. A vortex particleseparator with provision to prevent abrasion by separated particlesretained therein, comprising a tubular body having an inlet at one end,an outlet at the opposite end and a central passage therebetween; adeflector coaxially mounted in the passage adjacent the inlet, having aplurality of helical vanes abutting the wall of the passage, andpositioned at an angle to the line of flow from the inlet to the outletso as to create a vortex stream in the influent air, which concentratesthe contaminant particles in the whirling air stream at the periphery ofthe passage, thereby leaving the air at the center of the passagerelatively clean; a generally tubular outlet member disposed within thecentral passage at the outlet end of the tubular body, for delivery ofclean air from the central passage of the tubular body; said tubularoutlet member defining an annular contaminant chamber between theexterior of the outlet member and the interior wall of the centralpassage of the tubular body receiving and storing separated contaminantparticles; a wall extending between the tubular outlet member and thetubular body at the outlet end of the annular chamber at the outlet endof the tubular body, closing off the annular chamber at that end; andbaffle means comprising a plurality of radical fins which extend atleast partially across the annular chamber, to deflect the whirling airand particle flow and permit only axial flow, and define an inletopening into the annular chamber and through which all flow of air andseparated particles that enter the annular chamber must pass, the bafflemeans due to the absence of an outlet from the annular chamber beingeffective to deflect the whirling air stream in a manner to inhibit thewhirling movement of the particles retained in the chamber, and thusprevent abrasion of the wall of the tubular body there, substantiallywithout interfering with the entry of particles into the chamber, theinlet opening having an available open area such that at least someparticles that enter the annular chamber via the inlet opening cannotescape from the annular chamber.
 2. A vortex separator in accordancewith claim 1 in which the fins extend alternately from both the tubularoutlet member and the tubular body.
 3. A vortex separator in accordancewith claim 1 in which the radial fins extend completely across theannular chamber to form a plurality of segmented annular chambers.